Risk score for arch reconstruction under circulatory arrest with hypothermia: The ARCH score

OBJECTIVE

Currently, there is no risk scores built to predict risk in thoracic aortic surgery. This study aims to develop and internally validate a risk prediction score for patients who require arch reconstruction with hypothermic circulatory arrest.

METHODS

From 2002 to 2018, data for 2270 patients who underwent aortic arch surgery in 12 institutions in Canada were retrospectively collected. The outcomes modeled included in-hospital mortality and a modified Society of Thoracic Surgeons-defined composite for mortality or major morbidity. Multivariable logistic regression using least absolute shrinkage and selection operator selection method and mixed-effect regression model was used to select the predictors. Internal calibration of the final models is presented with an observed-versus-predicted plot.

RESULTS

There were 182 in-hospital deaths (8.0%), and the incidence of Society of Thoracic Surgeons-defined composite for mortality or major morbidity was 27.9%. Variables that increased risk of mortality are age, chronic obstructive pulmonary disease, atrial fibrillation, peripheral vascular disease, New York Heart Association class ≥III symptoms, acute aortic dissection or rupture, use of elephant trunk, concomitant surgery, and increased cardiopulmonary bypass time, with median c-statistics of 0.85 on internal validation. The c-statistics was 0.77 for the model predicting Society of Thoracic Surgeons-defined composite. Internal assessment shows good overall calibration for both models.

CONCLUSIONS

We developed and internally validated a risk score for patients undergoing arch surgery requiring hypothermic circulatory arrest using a multicenter database. Once externally validated, the ARCH (Arch Reconstruction under Circulatory arrest with Hypothermia) score would allow for better patient risk-stratification and aid in the decision-making process for surgeons and patient prior to surgery.

Retraction speed and chronic poststernotomy pain: A randomized controlled trial

OBJECTIVES

Approximately 30% of patients develop chronic poststernotomy pain (CPSP) following cardiac surgery with sternal retraction. Risk factors have been described but no causal determinants identified. Investigators hypothesized that opening the sternum slowly would impart less force (and thereby less nerve/tissue damage) and translate to a reduced incidence of CPSP. The main objectives were to determine whether or not slower sternal retraction would reduce the incidence of CPSP and improve health-related quality of life.

METHODS

Patients undergoing coronary artery bypass graft surgery were recruited to this randomized controlled trial. Patients were randomized to slow or standard retraction (ie, sternum opened over 15 minutes vs 30 seconds, respectively). Although the anesthesiologist and surgeon were aware of the randomization, the patients, assessors, and postoperative nursing staff remained blinded. Sternotomy pain and analgesics were measured in hospital. At 3, 6, and 12 months postoperatively, all patients completed the Medical Outcomes Survey Short Form and reported on CPSP and complications requiring rehospitalization. Thirty-day rehospitalizations and mortality were recorded.

RESULTS

In total, 326 patients consented to participate and 313 were randomized to slow (n = 159) versus standard retraction (n = 154). No clinically relevant differences were detected in acute pain, analgesic consumption, or the incidence of CPSP or health-related quality of life. Although the slow group had significantly more hospitalizations at 3 and 12 months postoperatively, the reasons were unrelated to retraction speed. No differences were observed in 30-day rehospitalizations or mortality.

CONCLUSIONS

All outcomes were consistent with previous reports, but no clinically significant differences were observed with retraction speed.

Effect of Cobalt-60 Calibration Dose-Rate on Arteriovenous Malformation Obliteration after Stereotactic Radiosurgery

PURPOSE/OBJECTIVE(S)

Stereotactic radiosurgery (SRS) dose rate - how old the cobalt-60 sources are - is known to influence outcomes for some neurologic conditions and benign tumors, but it is not known if SRS dose rate influences arteriovenous malformation (AVM) obliteration. The objective of this study is to determine the association between cobalt-60 calibration dose rate and cerebral AVM obliteration in patients treated with SRS. Our hypothesis is that higher SRS dose rates are associated with increased incidence of cerebral AVM obliteration.

MATERIALS/METHODS

We performed a retrospective study of 361 patients undergoing 411 AVM-directed SRS treatments between 2005 and 2019 at a single institution. Obliteration was confirmed with digital subtraction angiogram or MRI (if patient refused angiography). Lesion characteristics, SRS treatment details, and post-treatment obliteration and toxicities were recorded. Univariate and multivariate proportional hazards regression models of AVM outcomes with regard to SRS dose rate were performed, controlling for factors such as Spetzler-Martin Grade, maximum AVM extent, prior hemorrhage and prior embolization.

RESULTS

At 10 years post-SRS, 68% of AVMs were obliterated on follow-up imaging. Dose rates >2.9 Gy/min were found to be significantly associated with AVM obliteration compared to those <2.1 Gy/min (p = 0.034, Gray's test). AVM size or Spetzler-Martin grade were also associated with obliteration, with obliteration more likely for smaller lesions, particularly those <3 cm in maximal diameter, or with lower Spetzler-Martin grade. Higher dose rates were not associated with development of post-SRS radiologic or symptomatic edema, though larger AVM volume was associated with both types of edema.

CONCLUSION

Patients with cerebral AVMs treated with higher SRS dose rates (from fresh cobalt-60 sources) experience higher incidences of obliteration, without a significant change in the risk of post-treatment edema. These findings suggest that clinics offering SRS for AVMs should regularly renew cobalt-60 radiation sources to maintain high therapeutic dose rates.

Measurements of neutrino oscillation parameters from the T2K experiment using 3.6×1021 protons on target

The T2K experiment presents new measurements of neutrino oscillation parameters using 19.7 ( 16.3 ) × 10 20 protons on target (POT) in (anti-)neutrino mode at the far detector (FD). Compared to the previous analysis, an additional 4.7 × 10 20 POT neutrino data was collected at the FD. Significant improvements were made to the analysis methodology, with the near-detector analysis introducing new selections and using more than double the data. Additionally, this is the first T2K oscillation analysis to use NA61/SHINE data on a replica of the T2K target to tune the neutrino flux model, and the neutrino interaction model was improved to include new nuclear effects and calculations. Frequentist and Bayesian analyses are presented, including results on sin 2 θ 13 and the impact of priors on the δ CP measurement. Both analyses prefer the normal mass ordering and upper octant of sin 2 θ 23 with a nearly maximally CP-violating phase. Assuming the normal ordering and using the constraint on sin 2 θ 13 from reactors, sin 2 θ 23 = 0 . 561 - 0.032 + 0.021 using Feldman-Cousins corrected intervals, and Δ m 32 2 = 2 . 494 - 0.058 + 0.041 × 10 - 3 eV 2 using constant Δ χ 2 intervals. The CP-violating phase is constrained to δ CP = - 1 . 97 - 0.70 + 0.97 using Feldman-Cousins corrected intervals, and δ CP = 0 , π is excluded at more than 90% confidence level. A Jarlskog invariant of zero is excluded at more than 2 σ credible level using a flat prior in δ CP , and just below 2 σ using a flat prior in sin δ CP . When the external constraint on sin 2 θ 13 is removed, sin 2 θ 13 = 28 . 0 - 6.5 + 2.8 × 10 - 3 , in agreement with measurements from reactor experiments. These results are consistent with previous T2K analyses.

Impact of transcatheter aortic valve implantation on circulating von Willebrand factor in patients with severe aortic stenosis

INTRODUCTION

Severe aortic stenosis (AS) can lead to degradation of high molecular weight (HMW) von Willebrand factor (VWF) which can result in haemostatic abnormalities. While studies have explored changes in VWF profiles before and after surgical aortic valve replacement (SAVR), the longer-term changes in VWF profiles pre- and post-transcatheter aortic valve implantation (TAVI) are less understood.

AIM

Our primary objective was to identify differences in VWF multimer profiles and VWF function pre-TAVI and 1-month post-TAVI. Our secondary objective was to correlate VWF markers with measures of AS severity.

METHODS

Adult patients with severe AS referred for TAVI at our institution were prospectively enrolled in this cohort study. Blood samples were collected for plasma analysis at three time points for all patients: 1 day pre-TAVI, 3 days post-TAVI, and 1-month post-TAVI. VWF antigen, activity, propeptide, collagen binding, multimers, and factor VIII coagulant activity were determined at each time point. Correlations between VWF parameters and severity of AS were assessed.

RESULTS

Twenty participants (15 males, five females) with severe AS were recruited for the study. There was a significant increase in HMW VWF between pre-procedure and 1-month post-TAVI (p < .05). There was a transient increase in VWF antigen levels and activity at 3-days post TAVI that decreased to pre-TAVI levels at 1-month. There were no statistically significant correlations between VWF markers and AS severity.

CONCLUSIONS

This is the first study to elucidate longer-term (>1 week) improvements in HMW VWF after a TAVI procedure in severe AS patients.

Erector spinae plane block as perioperative analgesia for midline sternotomy in cardiac surgery: A systematic review and meta-analysis

BACKGROUND

Inadequate analgesia following cardiac surgery increases postoperative complications. Opioid-based analgesia is associated with side effects that may compromise postoperative recovery. Regional anesthetic techniques provide an alternative thereby reducing opioid requirements and potentially enhancing postoperative recovery. The erector spinae plane block has been used in multiple surgical procedures including sternotomy for cardiac surgery. We, therefore, aimed to characterize the impact of this block on post-sternotomy pain and recovery in cardiac surgery patients.

METHODS

We conducted an electronic search for studies reporting on the use of the erector spinae plane block in adult cardiac surgery via midline sternotomy. Randomized controlled trials, cohort studies, and case-control studies were considered for inclusion. Outcomes of interest included postoperative pain, time-to-extubation, and intensive care unit length of stay.

RESULTS

In total, 498 citations were identified and five were included in the meta-analysis. The erector spinae plane block did not significantly reduce self-reported postoperative pain scores at 4 h (-2.04; 95% confidence interval [CI] -8.15 to 4.07; p = .29) or 12 h (-0.27; 95% CI -2.48 to 1.94; p = .65) postextubation, intraoperative opioid requirements (-3.07; 95% CI -6.25 to 0.11; p = .05], time-to-extubation (-1.17; 95% CI -2.81 to 0.46; p = .12), or intensive care unit (ICU) length of stay (-4.51; 95% CI -14.23 to 5.22; p = .24).

CONCLUSIONS

Erector spinae plane block was not associated with significant reduction in postoperative pain, intraoperative opioid requirements, time-to-extubation, and ICU length of stay in patients undergoing cardiac surgery. The paucity of large randomized controlled trials and the high heterogeneity among studies suggest that further studies are required to assess its effectiveness in cardiac surgery patients.

Does Pacemaker Implantation After Surgical Aortic Valve Replacement Impact Long-Term Morbidity and Mortality? A Focused Review

Permanent pacing remains a serious complication that can occur in the postoperative period of surgical aortic valve replacement. The reported incidence is variable, and there are many perioperative factors that have been linked with a greater need for permanent pacing. Permanent pacing can also be associated with late lead-related and cardiac complications that can affect late outcome. However, the degree of late dependence on pacemakers is varied, and some studies have shown that a substantial proportion of patients do not need long-term pacing. Some groups have found that permanent pacing was associated with a negative impact on long-term survival in these patients. A common finding among these studies is that the groups of patients with pacemakers had higher preoperative surgical risk and comorbidity status. This makes it difficult to establish whether permanent pacing on its own represents a risk factor for late mortality or whether it is simply a marker that reflects the higher complexity and comorbidities in this group of patients.

The use of sutureless and rapid-deployment aortic valve prosthesis in patients with bicuspid aortic valve: A focused review

OBJECTIVE

The objective of this scoping review is to describe the postoperative outcomes and complications of patients with bicuspid aortic valve (BAV) treated with sutureless or rapid-deployment prosthesis.

BACKGROUND

The use of sutureless and rapid-deployment prostheses is generally avoided in patients with BAV due to anatomical concerns and the elevated risk of para-prosthetic leaks. Multiple studies have reported the use of these prostheses into patients with BAV with varying degrees of success. The focus of this review is to consolidate the current available evidence on this topic.

METHODS

A scoping review was conducted using a comprehensive search strategy in multiple databases (Medline, Embase, Cochrane Central Register of Controlled Clinical Trials) for relevant articles. All abstracts and full texts were screened by two independent reviewers according to predefined inclusion and exclusion criteria. Thirteen articles, including case reports and case series were ultimately included for analysis.

RESULTS

Of 1052 total citations, 44 underwent full text review and 13 (4 case reports, 6 retrospective analyses, and 3 prospective analyses) were included in the scoping review. Across all 13 studies, a total of 314 patients with BAV were used for data analysis. In sutureless and rapid-deployment prostheses, the mean postoperative aortic valvular gradients were less than 15 mmHg in all studies with mean postoperative aortic valvular areas all greater than 1.3 cm.² There were 186 total complications for an overall complication rate of 59%. Individual complications included new onset atrial fibrillation (n = 65), required pacemaker insertion (n = 24), intraprosthetic aortic regurgitation (n = 20), new onset atrioventricular block (n = 18), and new onset paravalvular leakage (n = 10).

CONCLUSIONS

The use of sutureless and rapid deployment prostheses in patients with BAV showed comparable intraoperative and implantation success rates to patients without BAV. Postoperative complications from using these prostheses in patients with BAV included new onset atrial fibrillation, intraprosthetic aortic regurgitation, new onset atrioventricular block, and required pacemaker insertion. Various techniques have been described to minimize these complications in patients with BAV receiving sutureless or rapid deployment prostheses.

Scintillation light detection in the 6-m drift-length ProtoDUNE Dual Phase liquid argon TPC

DUNE is a dual-site experiment for long-baseline neutrino oscillation studies, neutrino astrophysics and nucleon decay searches. ProtoDUNE Dual Phase (DP) is a 6  ×  6  ×  6 m 3 liquid argon time-projection-chamber (LArTPC) that recorded cosmic-muon data at the CERN Neutrino Platform in 2019-2020 as a prototype of the DUNE Far Detector. Charged particles propagating through the LArTPC produce ionization and scintillation light. The scintillation light signal in these detectors can provide the trigger for non-beam events. In addition, it adds precise timing capabilities and improves the calorimetry measurements. In ProtoDUNE-DP, scintillation and electroluminescence light produced by cosmic muons in the LArTPC is collected by photomultiplier tubes placed up to 7 m away from the ionizing track. In this paper, the ProtoDUNE-DP photon detection system performance is evaluated with a particular focus on the different wavelength shifters, such as PEN and TPB, and the use of Xe-doped LAr, considering its future use in giant LArTPCs. The scintillation light production and propagation processes are analyzed and a comparison of simulation to data is performed, improving understanding of the liquid argon properties.

Lung transplantation and concomitant cardiac surgical procedures: A systematic review and meta-analysis

BACKGROUND

Lung transplantation is an effective treatment option for end-stage lung diseases. In some cases, these patients may also have underlying cardiac disease which may require surgical intervention before or during transplantation. Concomitant cardiac surgery may often be preferred, as reduced lung function precludes these patients from pre-transplant surgery. Our meta-analysis sought to examine the impact of lung transplantation paired with concomitant cardiac surgery on long-term mortality.

METHODS

We conducted a systematic review of the MEDLINE, Embase, and Cochrane databases. Our primary outcome was overall mortality. Secondary outcomes included length of stay (LOS) in hospital and serious postoperative complication rates. We used a meta-analytic model to determine the differences in the above outcomes between patients who underwent lung transplantation with or without concomitant cardiac surgery.

RESULTS

Out of the 1876 articles screened, 7 met our pre-determined inclusion criteria. Lung transplantation with concomitant cardiac surgery was not associated with increased mortality compared to lung transplantation alone (hazard ratio = 1.02; 95% confidence interval [CI] = 0.80-1.31; I²  = 0%; p = .99). LOS in hospital was not significantly different between groups (standardized mean difference = 0.32; 95% CI = -0.91 to 1.55). Postoperative complication rates were also reported but not analyzed due to missing data.

CONCLUSIONS

There was no significant difference in mortality rates in patients undergoing lung transplantation with or without concomitant cardiac surgery at 1, 3, and 5 years. However, postoperative complication rates were higher in the concomitant group. The decision to perform concomitant procedures should be tailored to each patient's clinical condition.

Galectin-3 as a Predictor of Post Cardiac Surgery Atrial Fibrillation: A Scoping Review

PURPOSE

Galectin-3 is associated with myocardial fibrosis, a known risk factor for developing re-entrant circuits associated with atrial fibrillation (AF). Previous studies have demonstrated increased galectin levels in AF patients. Whether preoperative galectin-3 levels can predict the incidence of postoperative atrial fibrillation (POAF) remains unknown.

METHODS

This scoping review was conducted in accordance with the 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Electronic searches were conducted in Medline, EMBASE, Cochrane, and Google Scholar databases using a predetermined strategy. Methodological variables, demographics and operative data were extracted. Data extraction was performed manually by three reviewers.

RESULTS

The search yielded 620 citations, of which 74 underwent full text review, and 3 citations with 3 independent samples (n=1812) met full inclusion/exclusion criteria and were included. Of the three studies that reported on the association between preoperative galectin-3 levels and POAF, two studies compared median galectin levels in patients who developed POAF and those who did not. While Alexandre et al. reported a significant difference (p=0.002), Bening et al did not find a significant difference between POAF and non-POAF groups (p=0.3). A third study reporting on the association between galectin-3 and atrial fibrillation comparing 3rd and 1st tercile galectin-3 levels found a significant association between preoperative galectin levels and POAF on univariate analysis (OR 1.54; 95% CI 1.14-2.09).

CONCLUSIONS

Galectin-3 is an emerging biomarker that has been associated with the development of AF. However, there is currently not enough evidence to establish its prognostic role in post-cardiac surgery atrial fibrillation.

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

The use of FEIBA for refractory bleeding in cardiac surgery - a systematic review

INTRODUCTION

Significant blood loss during cardiac surgery is associated with a significant increase in morbidity and mortality. Factor Eight Inhibitor Bypassing Activity (FEIBA), a hemostatic bypassing agent mainly used in hemophiliac patients, has also been used for intractable surgical bleeding during cardiac surgical procedures in non-hemophiliac patients. However, concerns exist that its use may be linked to increased incidence of perioperative adverse effects including thrombotic complications.

AREAS COVERED

A systematic literature search was performed on MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials databases for all studies that reported the administration of FEIBA for treatment of bleeding during adult cardiac surgery in non-hemophiliac patients. After selecting of title and abstracts, two authors assessed the methodological quality of the full-text articles prior to final inclusion in the manuscript.

EXPERT OPINION

The safety profile of FEIBA was determined through an aggregate count of adverse events. Major complications included renal failure, re-operation for unresolved bleeding, postoperative mortality, and thromboembolic events. Overall, there is insufficient robust evidence to make a definitive conclusion about the safety or efficacy of using of FEIBA as a hemostatic agent in the setting of cardiac surgery.

CABG in patients with liver cirrhosis: to pump or not to pump?

INTRODUCTION

Coronary artery bypass grafting in patients with established liver cirrhosis is generally associated with poor outcomes. Avoiding cardiopulmonary bypass (CPB) in these patients has not demonstrated any advantage over the use of CPB. We review the current available literature that compared the outcome of both on-pump (ONCABG) and off-pump (OPCAB) techniques in cirrhotic patients in terms of morbidity and mortality.

AREAS COVERED

A comprehensive search was conducted in the PubMed/MEDLINE and EMBASE databases in January 2021. Articles that reported outcomes of OPCAB and/or ONCABG in cirrhotic patients with no concomitant surgical procedures were included. 829 unique abstracts were retrieved with title and abstract screening completed independently by two reviewers. Two case studies and six retrospective cohort studies were included. The largest study comprised more than 98% of the total population, showing some survival benefit for OPCAB over ONCABG. However, it was population-based and did not report the severity of liver. The remaining studies reported no clear difference in outcome between the two techniques.

EXPERT OPINION

: Surgical myocardial revascularisation carries high peri-operative risk in patients with liver cirrhosis irrespective of the surgical technique. There is a lack of evidence to suggest that avoiding CPB in these patients may be beneficial.

Evolving Surgical Techniques and Improving Outcomes for Aortic Arch Surgery in Canada

Background

To explore evolving surgical techniques and outcomes for aortic arch surgery.

Methods

A total of 2435 consecutive patients underwent aortic arch repair with hypothermic circulatory arrest between 2008 and 2018 in 12 institutions across Canada. Trends in patient characteristics, surgical techniques, and in-hospital outcomes, including major morbidity or mortality, were examined.

Results

From 2008 to 2018, the age of patients (62.3 ± 13.2 years) and the proportion of women (30.2%) undergoing arch surgery did not change significantly. Aortic diameters at operation decreased (2008: 58 ± 13 mm; 2018: 53 ± 11 mm; P < 0.01). Surgeons performed more valve-sparing root replacements (2008: 0%; 2018: 15%; P < 0.001) and fewer Bentall procedures (2008: 27%; 2018: 20%; P < 0.01). Total arch replacement rates were similar (P = 0.18); however, elephant trunk (2008: 9.5%; 2018: 19%; P < 0.001) and frozen elephant trunk (2008: 3.1%; 2018: 15%; P < 0.001) repair rates have increased. Over time, higher nadir temperatures (2008: 18 [17-21]°C; 2018: 25 [23-28]°C; P < 0.001), and more frequent antegrade cerebral perfusion (2008: 61%; 2018: 83%; P < 0.001) were used. For elective cases, in-hospital mortality rates declined (2008: 6.8%; 2018: 1.2%; P = < 0.01), as did major morbidity or mortality (2008: 24%; 2018: 13%; P < 0.001) and transfusion rates (2008: 61%; 2018: 41%; P < 0.001), but stroke rates remained constant (2008: 6.8%; 2018: 5.3%; P = 0.12). Outcomes remained the same over time for urgent or emergent cases.

Conclusions

Outcomes have improved over the past decade in Canada for elective aortic arch surgery, in the context of operating on smaller aortas, and more frequent use of moderate hypothermia and antegrade cerebral perfusion. Further research is needed to improve stroke rates and outcomes in the emergency setting.

Prospects for beyond the Standard Model physics searches at the Deep Underground Neutrino Experiment: DUNE Collaboration

The Deep Underground Neutrino Experiment (DUNE) will be a powerful tool for a variety of physics topics. The high-intensity proton beams provide a large neutrino flux, sampled by a near detector system consisting of a combination of capable precision detectors, and by the massive far detector system located deep underground. This configuration sets up DUNE as a machine for discovery, as it enables opportunities not only to perform precision neutrino measurements that may uncover deviations from the present three-flavor mixing paradigm, but also to discover new particles and unveil new interactions and symmetries beyond those predicted in the Standard Model (SM). Of the many potential beyond the Standard Model (BSM) topics DUNE will probe, this paper presents a selection of studies quantifying DUNE's sensitivities to sterile neutrino mixing, heavy neutral leptons, non-standard interactions, CPT symmetry violation, Lorentz invariance violation, neutrino trident production, dark matter from both beam induced and cosmogenic sources, baryon number violation, and other new physics topics that complement those at high-energy colliders and significantly extend the present reach.

Does adding an aortic root replacement or sinus repair during arch repair increase postoperative mortality? Evidence from the Canadian Thoracic Aortic Collaborative

 

OBJECTIVES

The aim of this study was to examine the effect of the addition of an aortic root replacement or sinus repair on mortality and morbidity during aortic arch repair.

METHODS

A total of 2472 patients underwent proximal or total aortic arch repair with hypothermic circulatory arrest between 2002 and 2018 at 12 centres. Multivariable logistic regressions (MV) and propensity score (PS) with inverse probability of treatment weighting (IPTW) analyses were performed.

RESULTS

A total of 1099 (44.5%) patients had additional aortic root replacement (n = 934) or sinus repair (n = 165). Those with aortic root interventions were younger (61 ± 13 vs 64 ± 13 years, P < 0.001) and had less females (23% vs 35%, P < 0.001), less dissection (31% vs 36%, P = 0.004), less urgent cases (35% vs 39%, P = 0.047), more connective tissue disease (7% vs 3%, P < 0.001) and less total arch replacements (14% vs 22%, P < 0.001). On adjusted analyses, the addition of aortic root procedure was associated with increased mortality [MV: odds ratio (OR) 1.41, 95% confidence interval (CI) 1.03-1.92; PS-IPTW: risk increased by 3.7%, 95% CI 1.2-6.3%, P = 0.004]. Reoperation for bleeding was also increased with the addition of aortic root intervention (MV: OR 1.48, 95% 1.10-1.99; PS-IPTW: risk increased by 3.2%, 95% CI 0.8-5.6%, P = 0.009). The risks of stroke and dialysis-dependent renal failure were similar. When looking only at non-elective cases, the increased risk of mortality was more pronounced (MV: OR 1.60, 95% CI 1.11-2.32, P = 0.013; PS-IPTW: risk increased by 6.8%, 95 CI 1.7-11.8%, P = 0.008, and a number need to harm of 15 patients to cause 1 additional death).

CONCLUSIONS

The addition of aortic root replacement or sinus repair during proximal or total aortic arch repair seems to increase postoperative mortality only in non-elective cases.

Predicting adverse cardiovascular outcomes in post-coronary artery bypass grafting patients using novel ECG frequency analysis of the QRS complex

Background

A novel metric called Layered Symbolic Decomposition frequency (LSDf) has been shown to be an independent predictor of ventricular arrhythmia and mortality in patients receiving implantable cardioverter‐defibrillator (ICD) devices. This novel index studies the fragmentation of the QRS complex. However, its generalizability to predict cardiovascular events for other cardiac procedures is unknown. Herein, we investigated the applicability of LSDf as a predictive measure for major adverse cardiovascular events (MACE) in patients receiving coronary artery bypass grafting (CABG).

Methods and Results

One hundred ninety‐five patients had high‐resolution ECG recorded prior to CABG surgery in 2012/2013 and were followed for a mean duration of 7.32 ± 0.32 years for postoperative cardiovascular outcomes. These outcomes were described as a modified composite of MACE defined as hospitalization for heart failure, ventricular tachycardia, ventricular fibrillation, and cardiovascular death including stroke and cardiac arrest. One hundred seventy‐two patients were included for analysis and 18 patients experienced a postoperative cardiovascular outcome. These patients had significantly increased age (71.3 vs. 64.6 years, p = .007), prolonged QRS duration (113.22 vs. 97.35 ms, p = .003), reduced left ventricular ejection fraction (42.7% vs. 56.5%, p < .001), and lower LSDf percent (13.5% vs. 16.9%, p = .002). Patients with an LSDf below 13.25% were 4.8 (OR 1.7–13.5, p < .001) times more likely to experience a MACE and up to 19.4 (OR 4.2–90.3, p < .001) times more likely to experience a MACE when older than 70 years and an ejection fraction below 50%.

Conclusion

Layered Symbolic Decomposition frequency may be an applicable metric to predict long‐term cardiovascular outcomes in patients with ischemic heart disease.

The Many Care Models to Treat Thoracic Aortic Disease in Canada: A Nationwide Survey of Cardiac Surgeons, Cardiologists, Interventional Radiologists, and Vascular Surgeons

Background

Several specialties treat thoracic aortic disease, resulting in multiple patient care pathways. This study aimed to characterize these varied care models to guide health policy.

Methods

A 57-question e-survey was sent to staff cardiac surgeons, cardiologists, interventional radiologists, and vascular surgeons at 7 Canadian medical societies.

Results

For 914 physicians, the response rate was 76% (86 of 113) for cardiac surgeons, 40% (58 of 146) for vascular surgeons, 24% (34 of 140) for radiologists, and 14% (70 of 515) for cardiologists. Several services admitted type B dissections (vascular 37%, cardiology 31%, cardiac 18%, other 7%), and care was heterogeneous. Ownership of disease management was overestimated relative to the perspective of the other specialties. Type A dissection admissions and treatment were more uniform, but emergent call coverage varied. A 24/7 aortic specialist on-call schedule was present only 4% of the time. “Aortic” case rounds promoted attendance by a broader aortic specialty contingency relative to rounds that were specialty specific. Although 89% of respondents felt an aortic team was best for patient care, only 54% worked at an institution with an aortic team present, and only 28% utilized an aortic clinic. Questions designed to define an aortic team derived 63 different combinations.

Conclusions

Thoracic aortic disease follows a network of undefined and variable care pathways, despite its high-risk population in need of complex treatment considerations. Multidisciplinary aortic teams and clinics exist in low volume, and the “aortic team” remains an obscure construct. A multispecialty initiative to define the aortic team and outline standardized navigation pathways within the health systems hospitals is advocated.

Economic Burden and Healthcare Resource Use for Thoracic Aortic Dissections and Thoracic Aortic Aneurysms-A Population-Based Cost-of-Illness Analysis

Background

Thoracic aortic dissections (TADs) and thoracic aortic aneurysms (TAAs) are resource intensive. We sought to determine economic burden and healthcare resource use to guide health policy.

Methods and Results

Using universal healthcare coverage data for Ontario, Canada, from 2003 to 2016, a cost‐of‐illness analysis was performed. From a single‐payer's perspective, direct costs (hospitalization, reinterventions, readmissions, rehabilitation, extended care, home care, prescription drugs, and imaging) were assessed in 2017 Canadian dollars. Controls without TADs or TAAs were matched 10:1 on age, sex, and socioeconomic status to cases with TADs or TAAs to compare posthospital service use to the general population. Linear and spline regression were used for cost trends. Total hospital costs increased from $9 M to $20.7 M for TADs (P<0.0001) and $13 M to $18 M for TAAs (P<0.001). Costs cumulated to $587 M for 17 113 cases. Median hospital costs for TADs were $11 525 ($6102 medical, $26 896 endograft, and $30 372 surgery) with an increase over time (P=0.04). For TAAs, median costs were $16 683 ($7247 medical, $11 679 endograft, and $22 949 surgery) with a decrease over time (P=0.03). Home care was the most used posthospital service (TADs 44%, TAAs 38%), but rehabilitation had the highest median cost (TADs $11.9 M, TAAs $11 M). Men had increased median costs for indexed hospitalizations relative to women, yet women used more posthospital services with higher service costs.

Conclusions

Total yearly costs have increased for TADs and TAAs. Median hospital costs have increased for TADs yet decreased for TAAs. Women use posthospital healthcare services more often than men.

Search for Electron Antineutrino Appearance in a Long-Baseline Muon Antineutrino Beam

Electron antineutrino appearance is measured by the T2K experiment in an accelerator-produced antineutrino beam, using additional neutrino beam operation to constrain parameters of the Pontecorvo-Maki-Nakagawa-Sakata (PMNS) mixing matrix. T2K observes 15 candidate electron antineutrino events with a background expectation of 9.3 events. Including information from the kinematic distribution of observed events, the hypothesis of no electron antineutrino appearance is disfavored with a significance of 2.40σ and no discrepancy between data and PMNS predictions is found. A complementary analysis that introduces an additional free parameter which allows non-PMNS values of electron neutrino and antineutrino appearance also finds no discrepancy between data and PMNS predictions.

The impact of age on patients undergoing aortic arch surgery: Evidence from a multicenter national registry

OBJECTIVE

Elderly patients are typically offered aortic surgery at similar diameter thresholds as younger patients, despite limited data quantifying their operative risk. We aim to report the incremental risk experienced by elderly patients undergoing aortic arch surgery.

METHODS

In total, 2520 patients underwent aortic arch surgery between 2002 and 2018 in 10 centers. Patients were divided into 3 groups: <65 years (n = 1325), 65 to 74 years (n = 737), and ≥75 years (n = 458). Outcomes of interest were in-hospital mortality, stroke, and the modified Society of Thoracic Surgeons composite for mortality or major morbidity (STS-COMP). Multivariable modeling was performed to determine the association of age with these outcomes.

RESULTS

As age increased, there was an increasing rate of comorbidities, including diabetes (P < .001), renal failure (P < .001), and previous stroke (P = .01). Rates of acute aortic syndrome (P = .50) and total arch repair were similar (P = .59) between groups. Older patients had greater mortality (<65: 6.1% vs 65-74: 9.0% vs ≥75: 14%, P < .001), stroke (6.3% vs 7.7% vs 11%, P = .01) and STS-COMP (25% vs 32% vs 38%, P < .001). After multivariable risk-adjustment, a step-wise increase in complications was observed in the older age groups relative to the youngest in terms of in-hospital mortality (65-74: odds ratio [OR] 1.57, P = .04; ≥75: OR, 2.94, P = .001) and STS-COMP (65-74: OR, 1.57, P < .001; ≥75: OR, 1.96, P < .001).

CONCLUSIONS

Older patients experienced elevated rates of mortality and morbidity following aortic arch surgery. These results support a more measured approach when evaluating elderly patients. Further research is needed on age-dependent natural history of thoracic aneurysms and size thresholds for intervention.

P6476Surgery does not appear to improve survival in patients with endocarditis and substance use disorder

Background

Cohort studies of surgery compared with medical treatment (MT) on endocarditis mortality are conflicting. We conducted a population-based study to estimate associations between treatment and mortality.

Methods

1,381 patients with substance use disorder (SUD) and 5,053 without (NSUD) hospitalized for endocarditis were included. Treatment was modeled as a time-dependent variable: patients who underwent surgery after admission were classified as MT until surgery occurred and surgically treated thereafter. Patients without surgery were classified as MT. Adjusted hazard ratios (aHR) between treatment and death (in-hospital, 30 days, one, two, five years) by SUD status were estimated.

Results

Among SUD patients, there was a trend towards reduction in in-hospital death with surgery vs. MT (aHR 0.61 [95% CI: 0.35–1.04]), but no difference at 30 days (aHR 0.79 [95% CI: 0.42–1.48]). Mortality was higher in SUD patients who underwent surgery compared with MT at one (aHR 1.30 [95% CI: 0.95–1.76]), two (aHR 1.27 [95% CI: 0.97–1.65]), and five years (aHR 1.37 [95% CI: 1.09–1.72]). In NSUD patients, in-hospital mortality (aHR 0.93 [95% CI 0.76–1.16]) did not differ, but 30 day mortality (aHR 1.36 [95% CI 1.04–1.77]) was higher with surgery versus MT, and lower at one (aHR 0.87 [95% CI: 0.73–1.03]), two (aHR 0.75 [95% CI: 0.64–0.88]), and five years (aHR 0.70 [95% CI: 0.61–0.81]).

Kaplan-Meier Survival Curves of Patients

Interpretation

Surgery compared with MT conferred no long-term survival benefit in SUD patients. In NSUD patients, surgery was associated with an initial increased risk of early death followed by a lower risk after one year.

Acknowledgement/Funding

Grant from Department of Surgery, Queen's University

A challenging Perceval valve implantation during concomitant mitral valve replacement with a bioprosthesis

In this video tutorial, we emphasize the main pitfalls in adequate sizing and expansion of the Perceval valve during a concomitant mitral valve replacement with a bioprosthetic. Following mitral valve replacement with a tissue-stented bioprosthesis, a transverse aortotomy was performed at 3 cm above the level of the aortic annulus. Three guiding sutures were then placed 120° apart in each valve sinus, 2-3 mm below the leaflet hinge point. The commissural struts of the mitral prosthesis can be seen in the aortic annulus. This positioning minimizes any potential protrusion in the left ventricular outflow tract.  Next, sizing of the Perceval was performed. The small transparent sizer fit nicely; however, a clear gap at the annulus could be appreciated with the small white sizer. The medium transparent sizer was then utilized, and it fit nicely; however, the medium white sizer was not able to pass through the aortic annulus. Given the gap present with the small sizer, we opted for a medium-size prosthesis. A medium Perceval prosthesis was parachuted into the aortic annulus with the help of the guiding sutures and the valve was deployed. Next, balloon expansion of the stent was performed. Given the potential concern of under-expansion of the stent, we opted for a longer dilatation at 4 atm for 1 min rather than the usual 30 sec. The aortotomy was then closed.

Surgical Removal of Migrated Broken Sternal Wire Using Endoscopic Assistance

Patients undergoing sternotomy routinely undergo sternal closure with stainless steel wires. Occasionally these wires can fracture, although normally this presents no concern as the broken wire remains fixed and is not problematic. We report a case of a segment of a broken sternal wire that migrated through the pericardium onto the right ventricular. It was removed with a minimally invasive approach with endoscopic assistance.

Endoscopic saphenous vein harvesting with a non-sealed approach

Endoscopic saphenous vein harvesting is considered a safe and effective approach for graft procurement during coronary artery bypass graft surgery. As an alternative to open techniques, minimally invasive approaches are associated with superior outcomes in terms of morbidity and patients' discomfort, without affecting graft quality, patency rate, and long-term outcomes.  Both sealed and non-sealed systems are available for endoscopic conduit harvesting. Sealed systems require carbon dioxide gas insufflation, which may have a damaging impact on the endothelium. Non-sealed systems do not require carbon dioxide insufflation and thus avoid the potential drawbacks of its use. In this video tutorial, we provide a thorough description of the surgical technique for endoscopic saphenous vein harvesting using a non-sealed approach.

Endoscopic radial artery harvesting with a non-sealed approach

Endoscopic radial artery harvesting is considered a safe and effective approach for graft procurement during coronary artery bypass graft surgery. As an alternative to open techniques, minimally invasive approaches are associated with superior outcomes in terms of morbidity and patients' discomfort, without affecting graft quality, patency rate, and long-term outcomes.  Both sealed and non-sealed systems are available for endoscopic conduit harvesting. Sealed systems require carbon dioxide gas insufflation, which may have a damaging impact on the endothelium. Non-sealed systems do not require carbon dioxide insufflation and thus avoid the potential drawbacks of its use. In this video tutorial, we provide a thorough description of the surgical technique for endoscopic radial artery harvesting using a non-sealed approach.

Search for CP Violation in Neutrino and Antineutrino Oscillations by the T2K Experiment with 2.2×10^{21} Protons on Target

The T2K experiment measures muon neutrino disappearance and electron neutrino appearance in accelerator-produced neutrino and antineutrino beams. With an exposure of 14.7(7.6)×10^{20} protons on target in the neutrino (antineutrino) mode, 89 ν_{e} candidates and seven anti-ν_{e} candidates are observed, while 67.5 and 9.0 are expected for δ_{CP}=0 and normal mass ordering. The obtained 2σ confidence interval for the CP-violating phase, δ_{CP}, does not include the CP-conserving cases (δ_{CP}=0, π). The best-fit values of other parameters are sin^{2}θ_{23}=0.526_{-0.036}^{+0.032} and Δm_{32}^{2}=2.463_{-0.070}^{+0.071}×10^{-3}  eV^{2}/c^{4}.

Combined Analysis of Neutrino and Antineutrino Oscillations at T2K

T2K reports its first results in the search for CP violation in neutrino oscillations using appearance and disappearance channels for neutrino- and antineutrino-mode beams. The data include all runs from January 2010 to May 2016 and comprise 7.482×10^{20} protons on target in neutrino mode, which yielded in the far detector 32 e-like and 135  μ-like events, and 7.471×10^{20} protons on target in antineutrino mode, which yielded 4 e-like and 66  μ-like events. Reactor measurements of sin^{2}2θ_{13} have been used as an additional constraint. The one-dimensional confidence interval at 90% for the phase δ_{CP} spans the range (-3.13, -0.39) for normal mass ordering. The CP conservation hypothesis (δ_{CP}=0, π) is excluded at 90% C.L.

Measurement of Coherent π^{+} Production in Low Energy Neutrino-Carbon Scattering

We report the first measurement of the flux-averaged cross section for charged current coherent π^{+} production on carbon for neutrino energies less than 1.5 GeV, and with a restriction on the final state phase space volume in the T2K near detector, ND280. Comparisons are made with predictions from the Rein-Sehgal coherent production model and the model by Alvarez-Ruso et al., the latter representing the first implementation of an instance of the new class of microscopic coherent models in a neutrino interaction Monte Carlo event generator. We observe a clear event excess above background, disagreeing with the null results reported by K2K and SciBooNE in a similar neutrino energy region. The measured flux-averaged cross sections are below those predicted by both the Rein-Sehgal and Alvarez-Ruso et al.

Measurement of Muon Antineutrino Oscillations with an Accelerator-Produced Off-Axis Beam

T2K reports its first measurements of the parameters governing the disappearance of ν[over ¯]_{μ} in an off-axis beam due to flavor change induced by neutrino oscillations. The quasimonochromatic ν[over ¯]_{μ} beam, produced with a peak energy of 0.6 GeV at J-PARC, is observed at the far detector Super-Kamiokande, 295 km away, where the ν[over ¯]_{μ} survival probability is expected to be minimal. Using a data set corresponding to 4.01×10^{20} protons on target, 34 fully contained μ-like events were observed. The best-fit oscillation parameters are sin^{2}(θ[over ¯]_{23})=0.45 and |Δm[over ¯]_{32}^{2}|=2.51×10^{-3}  eV^{2} with 68% confidence intervals of 0.38-0.64 and 2.26-2.80×10^{-3}  eV^{2}, respectively. These results are in agreement with existing antineutrino parameter measurements and also with the ν_{μ} disappearance parameters measured by T2K.